How To Tell If Mayonnaise Is Bad?

If you’ve ever wondered how to tell if mayonnaise is going bad, there are a few easy ways to tell. The consistency is uneven, and the oil separates from the liquid. If the mayo is past its sell-by date, it’s time to throw it out. If you’ve been using it for half a year or more, there’s a good chance that it’s gone wrong.


While it’s unlikely that your homemade mayonnaise is spoiled, it can be easy to spot if it’s spoiled. Its color will be yellow or brownish, and it will have lost its creamy texture. You’ll need to discard the jar as it’s spoiled. If the jar has gone wrong, there’s a good chance that the mold spores in it will grow. The jar will have a foul smell, but it’s still perfectly safe to eat.

Mayonnaise Nutrition Fact

Here’s a table for Mayonnaise Nutrition Facts per 100g serving with Percent Daily Values based on a 2,000-calorie diet:

Nutrition Facts Amount per serving (100g) % Daily Value*
Calories 680 34%
Total Fat 75g 115%
Saturated Fat 12g 60%
Trans Fat 0g 0%
Cholesterol 50mg 17%
Sodium 1300mg 54%
Total Carbohydrate 0.5g 0%
Dietary Fiber 0g 0%
Total Sugars 0.5g 0%
Protein 1.2g 2%
Vitamin D 0mcg 0%
Calcium 20mg 2%
Iron 0.4mg 2%
Potassium 70mg 2%

Note: Your daily values may be higher or lower depending on your calorie needs.

How To Tell If Mayonnaise Is Bad?

There are a few signs that mayonnaise has gone wrong. While a jar of mayonnaise has a shelf-life of several months, it doesn’t take long for it to turn unhealthy. If you’re unsure whether your mayonnaise is safe, it should be discarded as soon as it starts to develop a smell or color. A sour, vinegar-like smell will indicate that it’s spoiled.

Checking the jar’s best-before date is the most straightforward and dependable method. However, relying on this does not always work in your favor.

It’s possible that unsealed jars of mayo have been left out for hours or overnight and then returned to the refrigerator, so do a sniff test and examine carefully.

The good news is that there are specific telltale symptoms that your mayonnaise has gone wrong.

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Molds and spores

If you notice spores in your mayonnaise or mold around the jar’s neck, it’s a clear indication that the food has gone wrong, and you should discard it right away.

Also, never consider replacing the container because this will not prevent the mayo from spoiling. It’s safer to toss it out!


Giving your mayo a sniff is another way to detect whether it’s already rotten. When you open a container of poor mayonnaise, it usually has a somewhat acidic or nasty odor. If your mayonnaise is already this way, don’t consume it.


Checking the appearance of your mayonnaise is the simplest way to identify whether it has gone wrong or not. Rather than being white, spoilt mayonnaise is usually yellowish or brownish. You’ll also note that the substandard mayo lacks a creamy quality and has a layer of liquid on top of it.

This separation could also mean that the mayonnaise has been frozen and then thawed.


It’s possible that relying on your senses of smell and sight to determine whether or not your mayo is awful won’t always work. If that’s the case, a taste test is required.

Use a clean kitchen spoon to whisk the mayonnaise, then taste it gently. If your mayonnaise feels sour or “odd,” it’s a red flag, and you should discard it!

Mayonnaise Storage Suggestions

These storage pointers should help you get started.

To retain its quality, it is recommended that you perform these things once you acquire the product, whether you made it yourself or bought it at the grocery shop.

Keep unopened, professionally prepared mayonnaise at a cool, dry temperature away from heat sources.

To keep track of the mayo’s shelf life, look for the “Best if Used By,” “Best Before,” or “Best When Used By” date on the jar.

Allowing opened and professionally packaged mayo to sit out at room temperature is not a good idea.

Commercially prepared mayonnaise should be kept refrigerated once opened. Homemade mayonnaise should be stored refrigerated, and eaten within seven days.

Is It Possible To Freeze Mayonnaise?

Though freezing mayonnaise is unusual, it can extend the condiment’s shelf life. However, don’t expect a creamy texture after freezing the mayonnaise.

You don’t have to do something just because you CAN.

Mayonnaise is an emulsion in general. If you freeze it, the emulsion will most likely break when the mayo is thawed, causing the ingredients to separate.

Once the eggs and oil separate, the texture will change, and it will no longer be a creamy, spreadable condiment.


What Is The Best Way To Store Mayonnaise?

Your mayonnaise’s shelf life is determined by its freshness and storage conditions.

Mayonnaise, both unopened and ready-made, can stay up to four months in the pantry and a year in the refrigerator.

However, unless you’ve already opened the package or it’s been contaminated by other food or filthy utensils, you don’t need to refrigerate it.

This is because professionally produced mayonnaise is subjected to rigorous testing and contains chemicals and preservatives that inhibit bacterial development.

Instead, store it at a cool temperature in a dry location away from heat sources.

To check the shelf life of mayo, look for the “Best if Used By,” “Best Before,” or “Best When Used By” date on the package.

It’s best not to leave open, professionally packaged mayonnaise out at room temperature; instead, keep the creamy condiment refrigerated.

If properly preserved, opened mayonnaise can last up to two months in the refrigerator.

Meanwhile, homemade mayonnaise should be stored in the refrigerator and used within seven days of preparation.

Is It Acceptable To Leave Mayonnaise Uut Overnight?

No, it’s not a good idea to leave mayo out overnight.

Mayonnaise is prepared from oil, egg yolks, vinegar, or lemon juice, as we all know. These substances have a short shelf life.

Compared to professionally prepared mayo, homemade mayo has a higher risk of deterioration because the latter is fortified with additives that can eliminate hazardous bacteria like salmonella.

Furthermore, commercially prepared mayonnaise contains pasteurized eggs, lowering the risk of foodborne illness.

If you’re producing your mayonnaise at home, it’s best to consume the refrigerated food within four days, preferably the same day.

Also, keep in mind that eating mayo left out at room temperature overnight is NOT SAFE because bacteria grow pretty quickly in this storage state.

According to the USDA, food that has been left out for more than two hours at temperatures ranging from 40 to 140 degrees Fahrenheit should be thrown away immediately.

This appears to contradict what they say about mayonnaise, yet we prefer to keep our dishes refrigerated.


The most obvious way to determine if mayonnaise is spoiled is to check it for the “Best By” date. If the date is too late, the mayonnaise will be spoiled and have an off-odor. It’s not safe to eat spoiled mayonnaise. So, it’s best to dispose of it as soon as possible. However, if the jar is still sealed and the package is undamaged, it’s still a good bet to eat it.

You can also check the expiration date on the jar. If the mayonnaise is more than three months old, it’s already past its expiration date. In the meantime, it’s too fresh to be spoiled. It would help if you kept it in a refrigerator to avoid this problem. Once the jar has passed its expiration date, you can use it on your favorite foods. When it’s too late, it’s time to discard the mayo.